# 成绩等级判断

score = int(input("请输入成绩(1-100)："))
if score >= 90:
    print("等级：A")
elif 80 <= score < 90:
    print("等级：B")
elif 70 <= score < 80:
    print("等级：C")
elif 60 <= score < 70:
    print("等级：D")
else:
    print("等级：E")
